Surface treating machine



June 5, 1934. w. OELMANN 1,961,384

SURFACE TREATING MACHINE Filed Dec. 17, 1931 3 Sheets-Sheet l fi INVENTOE I June 5, 1934. w QELMANN 1,961,384

SURFACE TREATING MACHINE Filed Dec. 17, 1931 3 Sheets-Sheet 2 -Q' Z; ATTORNEY June 3 w. OELMANN SURFACE TREATING MACHINE Filed Dec. 1'7, 1931 3 Sheets-Sheet 5 INVENTZR I ATTORNEY Patented June 5, 1934 PATENT OFFICE UNITED STATES Inventia Patent Verwertungs Schaffhausen, Switzerland Gesellschaft.

Switzerland, a corporation of Application December 17, 1931, Serial No. 581,616 In Germany August 24, 1931 19 Claims.

This invention relates to surface treating machines and more particularly to floor polishing machines and the like, having a plurality of rotatable members adapted to contact a surface such as a floor. Still more particularly the invention relates to a floor polishing machine having two or more rotatable implement discs, one

or more of which are frictionally driven by a rotating shaft in a given direction and the others of which are frictionally driven by the first-mentioned discs in reverse direction.

In a machine of the above type it is desirable to interrupt the rotation of the discs when the operating handle is placed in a vertical position or when the handle falls to the floor so that the machine will be stationary when not under direct control of the operator and will not walk and mar or injure furniture or other articles. It is accordingly an object of the present invention to provide an automatic control for disconnecting the driven discs from the source of power when the operating handle is in other than operating or active position.

A further object is to provide a convenient, simple and trustworthy control of the above character which may be incorporated in a machine without materially increasing the cost thereof.

In the preferred embodiment of the invention, driven discs are mounted so as to have move- 3 3 ment transverse to their axes, as for example on slidable yokes or supports and mechanical means, such as cooperating cam surfaces, are provided, which are operated by the main operating or directing handle of the machine and cause transverse movement of the yokes or supports for bringing the discs out of power transmitting relation with the power source whenever the handle is raised or lowered beyond its normal operating range.

The invention also consists in certain new and original features of construction and combinations of the parts hereinafter set forth and claimed.

Although the novel features which are believed to be characteristic of this invention will be particularly pointed out in the claims appended hereto, the invention itself, as to its objects and advantages and the manner in which it may be carried out may be better understood by referring to the following description taken in connection with the accompanying drawings forming a part thereof of which:

Fig. 1 is a side elevation of a floor treating machine constructed in accordance with the present invention;

Fig. 2 is a side elevation partly in section of the operating mechanism of the machine;

Fig. 3 is a horizontal section taken on the line 8-3 of Fig. 2;

Fig. 4 is a vertical section taken on the line 00 4-4 of Fig. 3;

Fig. 5 is a section taken on the line 5-5 of Fig. 2;

Fig. 6 is a detail plan view showing the slidable yokes and operating mechanism therefor; 5

Fig. 7 is a section taken on the line 7-7 of Fig. 6;

Fig. 8 is a section taken on the line 88 of Fig. 7;

Fig. 9 is a vertical section showing the operating mechanism for the yokes in position corresponding to a depressed position of the operating handle;

Fig. 10 is a section taken on the line 10--10 of Fig. 9; i

Fig. 11 is a diagrammatic representation of the driving mechanism showing the driven members disengaged from the driving shaft; and

Fig. 12 is a similar diagrammatic representation showing the members in driving engagement.

Like reference characters denote like parts in the several figures and drawings. In the following description and in the claims various details will be identified by specific names for convenience but they are intended to be as generic in their application as the art will permit.

Referring more particularly to Figs. 1 to 5, the floor polishing or treating machine is shown as comprising a casing 10, enclosing a source of power, such as motor 11 which is mounted with 9 its shaft 12 in a vertical position. The casing includes a lower annular member 13 which is provided at its base with an enlarged section 14 in which a bearing 15 for the shaft 12 is mounted. Member 13 also carries suitable brushes 16 (Fig. 5) which cooperate with commutator 17 of the motor in the usual manner. The casing is also provided with a cap 18 which is adapted to enclose the top thereof and the various parts of the casing are secured together in any desired manner.

An operating handle 20 is formed with a lower yoke section 21 which extends on opposite sides of the casing and is rigidly connected to a rod 22 which passes through annular member 13 and is rotatably mounted therein as by bearings 23. Secured to said yoke section 21 is a latch 25 which is pivoted as by pin 26 and is provided with a projection 27 which is adapted to engage a recess- 28 in cap 18 for purposes of holding the handle in vertical position. Lever 25 may be also provided with a roughened surface 30 which may be engaged by the foot of the operator for causing slight pivotal movement of said lever for disengaging the same from cap 18 and releasing the handle. Suitable means such as a spring may be provided for normally maintaining the lever in engaging position.

For supporting the operating mechanism there is provided a frame plate 33 which constitutes the major part of the frame work of the apparatus. Said frame plate includes an upstanding annular flange 34 between which and the lower part of annular member 13 is clamped an inturned flange 35 formed on hood 36. Hood 36 serves as a protecting covering for the surfacing parts of the machine to be described and at its lower part may be provided with a protecting flange 37 which may be formed of resilient material to prevent injury to furniture or other articles with which the machine may come in contact. Frame plate 33 may be secured to annular member 13 in any convenient manner as by bolts 40 which extend therethrough. Frame plate 33 is milled so that a portion of the under surface33a-is smooth and flat for the purpose to be set forth.

A fixed support 42 shown more in detail in Fig. 4 may be formed on or secured to frame plate 33 and comprises a flange 43 carrying a ball race 44 forming a part of the bearing for a rotatable carrier or implement disc 45 which is provided with a central hub member 46 having a ball race 47 secured therein which is complementary to ball race 44 above mentioned. A shield 48 may be secured to hub member 46 for shielding the bearing from dust and other foreign matter. The rotatable member 45 is termed a carrier disc inasmuch as it carries the implement, such as brush disc 50. Said brush disc is preferably proided with catches 51 which snap into sockets 52 formed in said carrier disc 45 in a manner more definitely set forth in the copending application of Engberg et al., Serial No. 286,663, filed June 19, 1928, Pat. No. 1,901,497, the arrangement being such that the implement disc may be readily detached from the carrier disc for purposes of cleaning, inspection or shifting of brushes with respect to carrier discs.

It will be noted that carrier disc 45 is mounted for rotation about a vertical axis which is fixed with respect to frame plate 33. The disc 57. Said washers 5'7, which may be formed of rubber or other similar material, serve not only to space guide plate 55 but also act as stops for limiting the horizontal movement of supporting or yoke members 58 about to be described.

In addition to carrier disc 45, the machine also includes a pair of carrier discs 60 which are similar in construction to carrier disc 45 and carry implement discs or brushes 61. Inasmuch as the construction of the two discs 60 and their supports are identical they have been given the same reference numerals and the following description will be applied particularly to only one of said discs in order to avoid a needless duplication. Referring more particularly to Fig.

4, disc 60 is shown as formed with a hub member 62 engaging a bearing 63 carried on a projection 64 formed 'on a supporting or yoke member 58, the construction of the, bearing being similar to that described in connection with carrier disc 45. Disc 60 is also provided with an upstanding flange 66 carrying a tire 67 which is maintained in frictional engagement with tire 54 of disc 45 as shown in Fig. 3 and with a driving element as will be pointed out.

' Yokemember 58 includes a forked section 70 having a slot 71 therein adapted to receive spring 72, one end of which is secured to said yoke member as by engaging a recess 73 formed therein and the other end of which is anchored to frame plate 33 as by a bolt or rivet 74 which is carried by said frame plate and. extends downwardly therefrom. The forked section '70 of yoke 58 is formed with parallel top and bottom surfaces and is dimensioned for sliding between the parallel surfaces of frame plate 33 and guide plate 55, the arrangement being such that free horizontal movement of said yoke member is permitted but vertical movement thereof is substantially prevented.

Yoke member 58 is also provided with a cam section 75 which has a rounded edge '76 forming a cam surface as illustrated in Fig. 5 and engages a cam member or pin 77 which is slidably mounted in a suitable bore in extension 14 of annular member 13. Pin 77 is provided with sections 78 and 79 of given diameter and an intermediate section 80 of smaller diameter. The dimensions of said sections are such that sections '78 and 79 engage cam surfaces 76 of yoke members 58 when they are brought into alignment therewith and thereby serve to separate said yoke members.-

The diameter of section 80, however, is such that when this section is brought into alignment with the yoke members, it is disengaged from cam surfaces 76 and thereby permits said yoke members to move together whereby discs 60 are caused to engage a driving member.

Pin 77 is in operating engagement with arm 82 which is mounted on rod 22 and secured thereto as by a set screw 83. Arm 82 is provided with an elongated slot 84 engaging a projection 85 on said pin 77 for furnishing the operating connection. The arrangement is such that when operating handle 20 is in vertical position, pin

77 is brought into its lower position illustrated in Figs. 2 and 5, and surface 78 is in engagement with cam surfaces 76 of yoke members 58. When handle 20 is in its lower or horizontal position, pin 77 is elevated to the position illustrated in Figs. 9 and 10 thereby bringing surface 79 into engagement with cam surfaces 76. It will be noted that in either of these positions the cam surfaces are separated. When handle 20 is in an intermediate position, as will be the case when the machine is being operated, pin 77 is also in an intermediate position as illustrated in Figs. 6, 7 and 8 and surface 80 is brought into alignment with cam surfaces 76 thereby releasing the yoke members.

For driving discs 60 the lower end of shaft 12 is provided with a friction surface 95 which .may be formed integrally therewith or may be formed of frictional material and secured thereto as by bolt 96. Said surface is adapted normally to engage tires 67 of discs 60 and to thereby drive said discs, the arrangement being that illustrated in Fig. 12. Springs 72 have suflicient tension to maintain discs 60 in engagement with friction v source of power.

tion.

surface 95 and with disc 45 so that a driving connection is established between shaft 12 and discs 60 on the one hand and between discs 60 and disc 45 on the other hand. It will be noted that discs 60 are both rotated in a given direction and that disc 45, which is driven thereby, is rotated in a reverse direction. Furthermore the drive between the various elements is entirely frictional and is brought about by the force exerted by springs 72. The forked section of yoke members 58 is preferably so formed as to cooperate with springs 72 for maintaining the correct position of said yoke members and the corners of said yoke members adjacent slot 71 may be rounded to prevent them from catching on said spring.

When yoke members 58 are separated as by surfaces 78 or '79 of pin 7'7, discs 60 are moved out of engagement with driving surface 95 and are then in a position diagrammatically illustrated in Fig. 11 in which shaft 12 is free to rotate but does not cause rotation of any of the driven discs. This condition corresponds to the vertical or horizontal position of the operating handle in which it is desired to interrupt the operation of the machine.

The taper between surfaces 78 and 79 and surface 80v of pin 7'7 bears a relation to the cam surfaces 76 such that the tension of spring '72 serves to produce a quick action between the three above described positions of pin '77 whereby discs 60 are at all times either in full engagement with driving surface 95 or are entirely disengaged therefrom. This prevents the discs from being in partial engagement with said surface whereby slippage might take place with consequent wear of the surfaces. A certain amount of lost motion is obtained by means of projection and slot 84 which assists in obtaining the above mentioned quick action.

In certain instances, as for example in polishing a floor under low furniture, it may be desired to operate the device with handle 20 in a horizontal position. In order to permit this to be accomplished, pin 77 is preferably formed with the part carrying surface '79 removable therefrom, for example, by constructing part '79 separately and threading or otherwise attaching the same to pin 77.

The friction drive by which the discs are driven in opposite directions by means of friction engagement with the driving shaft is disclosed in a copending application Ser. No. 568,980, Patent No. 1,915,495. It will be noted that in accordance with the present invention the polishing apparatus is maintained in operation whenever the operating handle is in its normal operating posi- If, however, the handle should be dropped to the floor or should be elevated to vertical position, as for example at the completion of the polishing operation, the carrier discs and operating implements or brushes are disconnected from the There is accordingly no possibility of the device remaining in active operation except under the attendance of an operator.

While certain novel features of the invention have been disclosed and are pointed out in the appended claims, it will be understood that various omissions, substitutions and changes may be made by those skilled in the art without departing from the spirit of the invention.

What I claim is:

1. In a surface treating machine, a casing, a motor in said casing having a shaft, a relatively long control handle pivotally mounted on said casing to have an operating position in which the handle extends materially above the casing, said handle serving to guide the machine in operation, a disc adapted to carry surface treating implements, members providing a driving connection between said shaft and said disc, means to interrupt said driving connection and means operatively connected to the handle and controlled in accordance with the position of said handle for operating said first means.

2. In a surface treating machine, a casing, a motor, a disc, mounting structure for said disc allowing the disc to have horizontal movement, means including separable members providing a driving connection between said motor and said disc, a handle pivotally mounted on said casing to have an operating position in which the handle extends materially above the casing, said handle serving to guide the machine in operation, and a spreading member having an irregular surface adapted to engage the disc mounting structure to move the disc horizontally to separate said separable members to interrupt said driving connection, said spreading means being operatively connected to the handle whereby movement of the handle actuates the spreading 1 member to make or break the driving connection.

3. In a surface treating machine, a casing, a motor in said casing, a rotatable disc, mounting means for said disc, frictional driving means for said discconnected to said motor, means for normally maintaining saiddisc in frictional engagement with said driving means, a relatively long opera-ting handle for said machine mounted on said casing to have pivotal movement about a horizontal axis and having an operating posi-- 1 tion in which the handle extends materially above the casing, and reciprocal means having an irregular surface and connected to and controlledby the angular position of said handle and arranged to contact the disc mounting means to 1 move the same laterally for permitting and interrupting frictional driving engagement of the driving means and the disc.

4. In a surface treating machine, a casing, a motor in said casing, an operating handle pivotally mounted on said casing to have an operating position in which the handle extends materially above the'casing, said handle serving to guide the machine in operation, a rotatable disc,

means for mounting said disc for rotational ,-:5"

movement about avertical axis and for transverse horizontal movement, a drivin' member connected to said motor and rotatable about a vertical axis, means for normally maintaining said disc and said driving member in driving on- .7

relatively long operating handle mounted on said casing to have pivotal movement in a vertical plane, a disc mounted for rotation about a vertical axis, a support for said disc, means for mounting said support for sliding horizontal movement,

a vertical drive shaft, a motor for driving said shaft, resilient means for normally maintaining said disc in driving engagement with said shaft and'a movable member connected to said handle and controlled by the position of said handle for causing horizontal movement of said support and 153 disengaging said disc from said shaft when said handle is in other than working positions, said handle being so long as to extend materially above said casing in certain positions and being operative to guide the machine.

6. In a surface treating machine, a casing, a relatively long handle mounted on said casing to have pivotal movement in a vertical plane, a vertical drive shaft, a motor on said shaft, a rotatable disc, means for mounting said disc for rotation about a vertical axis comprising a supporting member, said supporting member being mounted for slidable movement in a horizontal plane, means for normally maintaining said disc in driving engagement with said shaft, a cam surface formed on said supporting member and a cooperating cam member operatively connected with said handle and operated thereby to cause movement of said supporting member and thereby bring said disc out of engagement with said drive shaft when said handle is in certain positions, said handle being so long as to extend materially above said casing in certain positions and being operative to guide the machine.

7. In a surface treating machine, a casing, a relatively long handle mounted on said casing to have movement in a vertical plane, a rotatable disc, a supporting member therefor mounted to have horizontal movement, means for mounting said disc on said supporting member for rotational movement about a vertical axis, a vertical drive shaft, a motor for driving said shaft, resilient means acting on said supporting member for normally maintaining said disc, in driving engagement with said shaft, said supporting member having a cam surface formed thereon and a cam member in operative engagement with said handle, said cam member having a pair of surfaces adapted to engage said first cam surface for shifting said supporting member laterally and an intermediate surface adapted to release said supporting member, said cam member being so associated with said handle that the cam surfaces thereof engage said supporting member when the said handle is in vertical or horizontal positions and the intermediate surface is brought into alignment with said supporting member and disengaging the same when said handle is in working position.

8. In a surface treating machine, a rotatable carrier disc, a yoke supporting said disc for rotational movement, said machine having a frame,

means for slidably mounting said yoke in said frame for lateral movement, a driving member carried by said frame, a motor connected to said driving member said disc being in frictional engagement with said driving member, said yoke having a cam surface formed thereon, an operating handle for said machine and a cam member mechanically connected thereto and having different positions for different angular positions of said handle and adapted to engage said cam surface when said handle is in either vertical or horizontal positions for' shifting said yoke laterally and thereby breaking the frictional driving engagement between said disc and said shaft, said handle being so long as to extend materiallyporting member, means for slidably mounting said supporting member in said frame, resilient means for normally holding said second disc in frictional engagement with said drive shaft and with said first disc whereby said discs are normally rotated in opposite directions, a handle pivotally mounted on said frame and adapted to be moved into and out of working position, and a member connected to'said handle and movable in accordance with the position thereof and having an irregular surface for causing lateral movement of said supporting member when said handle is in other than working positions, said lateral movement serving toshift said second disc out of engagement with said drive shaft and to thereby break the driving connection between said source of power and said disc, said handle being so long as to extend materially above said casing in certain positions and being operative to guide the machine.

' 10. In a surface treating machine, a frame,

driving mechanism mounted thereon comprising a vertical drive shaft, a carrier disc, means for mounting said carrier disc on said frame for rotation about a fixed vertical axis, a second carrier disc, means for mounting said second carrier disc for rotation about a floating vertical axis, means for normally holding said second carrier disc in driving engagement with said first disc and with said drive shaft whereby said discs are driven in opposite directions by said shaft, an operating handle pivotally mountedon said frame and movable in a vertical plane and a member connected to said handle for causing lateral movement of said second disc and breaking the driving engagement between said disc and said shaft when said handle is in other than working positions, said handle being so long as to extend materially above said casing in certain positions and being operative to guide the machine.

11. In a surface'treating machine, a frame, a driving shaft mounted on said frame for rotation about a vertical axis, a rotatable carrier disc, means for mounting said disc on said frame for rotation about a fixed vertical axis, a guide plate mounted below said frame and spaced therefrom to provide a horizontal channel, a yoke mounted Within said channel for horizontal movement therein, a second carrier disc mounted for rotational movement on said yoke, means associated with said yoke for normally maintaining said second disc in driving engagement with said'first disc and with said vertical drive shaft, an operating handle for said machine pivotally connected to said frame, said yoke having a cam surface formed thereon and a cam member operated by said handle and engaging said surface for causing lateral movement of said yoke when said handle is in vertical or horizontal positions in such direction as to shift said second carrier disc out of driving engagement with said vertical drive shaft to interrupt the operation of said machine.

12. In'a surface treating machine, a frame, a

driving shaft mounted on said frame for rotation about a vertical axis, a rotatable carrier disc, means for mounting said disc on said frame for rotation about a fixed vertical axis, a guide plate mounted below said frame and spaced therefrom to provide a horizontal channel, a yoke mounted within said channel for horizontal movement therein, a second carrier disc mounted for rotational movement on said yoke, means associated with said yoke for maintaining said second disc in driving engagement with said first disc and with said vertical drive shaft in normal operation, an operating handle for said machine pivotally connected to said frame, and means interconnecting said handle and said yoke for causing lateral'movement of said yoke in said channel whereby'said second disc is brought out of engagement with said drive shaft when said handle is movedinto other than working positions.

13. In a surface treating machine, a frame, a driving shaft mounted on said frame for rotation about a vertical axis, arotatable carrier disc, means for mounting said disc on said frame for rotation about a fixed vertical axis, a guide plate mounted below said frame and spaced therefrom to provide a horizontal channel, a pair of yoke members mounted for slidable movement in said channel, carrier discs rotatably mounted in said yoke members, resilient means associated with saidyoke members and with said frame for normally maintaining said second-mentioned carrier discs in driving'engagement with said vertical shaft and with said first-mentioned disc, a handle pivotally mounted on said frame, a cam member mounted in said frame and operatively connected to said handle, cam-surfaces formed on said yoke members and engaging said cam member, said cam member being so constructed as to cause lateral movement of said yoke members in such direction as to bring said secondmentioned discs out of engagement with said driving shaft when said handle is moved out of working positions.

14. In a surface treating machine or the like, a frame, a drive shaft mounted on said frame for rotation about a vertical axis, a rotatable carrier disc, means for mounting said disc on said frame for rotation about a fixed vertical axis, a guide plate mountedbelow said frame and spaced therefrom to provide a horizontal channel, a pair of yoke members mounted for slidable movement within said channel and carrying ro tatable discs, said yoke members having cam surfaces, means for holding said discs and drive shaft in motion transmitting engagement, a pin having cam surfaces adapted to cooperate with the cam surfaces on the yoke members, means for mounting said pin for slidable movement in said frame, an operating handle for said machine pivotally connected to said frame and means interconnecting said handle and'said pin whereby said cam surfaces cause lateral movement of said yoke members whenasaid handle is moved between working and non-working positions to move the discs mounted on the yoke members into and out of moticn transmitting engagement with the drive shaft.-

15. In a surface treating machine, a frame, a

drive shaft supported thereon, a rotatable carrier disc, means for mounting said carrier disc on said frame for rotational movement about a fixed vertical axis, a second carrier disc, means for mounting said second disc for rotational movement about a floating vertical axis, said means comprising a yoke member slidably associated with said frame, resilient means for normally holding said second carrier disc in driving engagement with said drive shaft and with said first carrier disc, an operating handle for said machine pivotally secured to said frame, and means interconnecting said handle and said yoke for causing lateral movement of said yoke when said handle is in other than operating position to thereby break the driving connection between said seconddisc and said shaft, said last-mentioned means including a lost motion connection members and thereby breaking the between said handle and'said yoke whereby a quick action is obtained between operating and. non-operating positions of said second disc for preventing said disc from being in partial engagement with said drive shaft.

16. In a surface treating -machine, a fixed frame, an operating handle pivotally mounted thereon, a driving member including a source of power mounted on said frame and having a vertical drive shaft, a rotatable carrier disc, means for mounting said disc on said frame for rotational movement about a fixed vertical axis, a second carrier disc, means for mounting said-second disc for rotational movement about a floating vertical axis, resilient means for normally go maintaining said second disc in driving engagement with said driveshaft and with said first disc, a cam member slidably mounted in said I framecomprising a plura.lity of separable parts, an operating connection between said cam member and said handle, means adapted to engage said cam member for causing lateral movement of said second disc when said handle is moved to vertical or horizontal position for thereby bringing said second disc out of driving engagement with said drive shaft, the part of said cam member which normally causes movement of said disc when said handle is moved into horizontal position being removable from said cam member whereby said machine may be operated with the handle in horizontal position when desired.

17. In a surface treating machine, a frame, a handle pivotally mounted thereon, a first carrier disc rotatably mountedin said frame for rotation about a fixed vertical axis, a pair of second carrier discs, means for rotatably mounting said second carrier discs for movement about a float-- ing vertical axis comprising yoke members carry ing said second discs and slidably mounted in said frame, a vertical drive shaft carried in said frame and a source of power therefor, resilient means for holding said second discs in driving engagement with said first disc and with said drive shaft in normal operation, cam surfaces formed on said yoke members, a. pin slidably mounted in said frame, said pin having surfaces adapted to engage said cam surfaces for causing transverse movement. of said yoke members in such direction as to break the driving engagement between said drive shaft and said second discs and means interconnecting said pin and said handle for causing movement of said pin in response to pivotal moyement of said handle for bringing the cam surfaces of said pin into engagement with the cam surfaces of said yoke driving connection between said drive shaft and said second discs when said handle is in other than working positions.

18. In a surface treating machine, a fixed frame, an operating handle pivotally mounted thereon, a driving member including a source of power mounted on said frame and having a ver-, tical drive shaft, a rotatable carrier disc, means for mounting said disc for rotational movement on said frame, a yoke member slidably mounted on said frame, a second carrier disc rotatably mounted on said yoke member, resilient means associated with said yoke member and with said frame for maintaining said second disc in driving engagement with said drive shaft and with said first disc in normal operation, a cam member slidably mounted in said frame, a lost motion operating connection between said cam member and said handle, a cam surface formed on said 150 yoke member and adapted to engage corresponding surfaces on said cam member for causing lateral movement of said yoke member when said handle is moved into vertical or horizontal position in such direction as to bring said second disc out of driving engagement with said drive shaft, said resilient means and said lost motion connection providing a quick action for said cam member between its operating positions.

19. In a surface treating machine, a frame, a handle pivotally mounted thereon, a first carrier disc rotatabLv mounted on said frame for rotation with said first disc and with said drive sum in normal operation, cam'surfaces formed on said j yoke members, a pin slidably mounted in said frame for vertical movement, said pin having surfaces adapted to' engage said cam surfaces for causing transverse movement of said yoke members in such direction as to break the driving engagement between said drive shaft and said second discs and means interconnecting said pin and said handle for causing movement of said pin in response to pivotal movement of said handle for bringing the cam surfaces of said pin into engagement with the cam surfaces of said yoke members and thereby breaking the driving connection between said drive shaft and said second discs when said handle is in other than working positions and means including said resilient means for providing a quick action for said pin between its various operating positions.

WILHEIM OELMANN. 

